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Aminoazaphtalocyanine peripheral substitution effect on J-dimer formation
Machan, Radek ; Zimčík, Petr (advisor) ; Zitko, Jan (referee)
Charles University, Faculty of Pharmacy in Hradec Kralove Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Author: Mgr. Radek Machan Supervisor: prof. PharmDr. Petr Zimčík, Ph.D. Rigorosum thesis: Aminoazaphtalocyanine peripheral substitution effect on J-dimer formation Azaphthalocyanines (AzaPcs) are classified as subgroup of phthalocyanine family, which are planar synthetic macromolecules derived from naturally occurring porphyrins. AzaPcs are aza-analogues of phthalocyanines, where benzenes are isosterically replaced by nitrogen heterocycles (pyrazine, pyridine or pyridazine). Due to the extensive system of conjugated double bonds, AzaPcs exhibit interesting photophysical properties, for which they are commonly used as industrial dyes, photosensitisers in photodynamic therapy, fluorescent sensors, fluorescence quenchers etc. Octakis(dialkylamino) substituted tetrapyrazinoporphyrazines (TPyzPzs), which belong to the AzaPcs family, can be used as effective fluorescence quenchers due to their ability to relax from excited state by intramolecular charge transfer (ICT) that leads to zero intrinsic fluorescence. This thesis deals with the preparation and subsequent study of the properties of symmetric TPyzPzs. Above all, the ability of TPyzPzs to form aggregates of the...
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Comprehensive characterization of cellular suspensions by means of elastic light scattering
Macháň, Radek ; Štěpánek, Josef (advisor) ; Plášek, Jaromír (referee)
Studies of yeast Saccharomyces cerevisiae - a model eukaryot organism - often require determining the number of cells in a suspension. One of the methods often used for studying cell suspensions is the measuring of elastic scattering of light passing through the suspensions. Usual output of those measurements is the angular dependency of the intensity of scattered light, which bears information about the size of scatterers. This thesis studies time-dependencies of the intensity of scattered light and relationship of their statistical properties to the number of scatterers in a unit volume. For this purpose a simple model was proposed, which describes the connection between this quantity for a monodisperse suspension and the dependency of standard deviation of time-behaviour of the scattered intensity on the mean value of the same time-behaviour. An apparatus for computer controlled measurements of angular and timedependencies of scattered light intensity was completed for carrying out the experiments. Elastic scattering was measured on suspensions of yeast Saccharomyces cerevisiae and a model system (suspensions of 8m polymer particles). Experimental data were interpreted within the proposed model. Although yeast suspensions cannot be regarded as monodisperse, experimental data were in a good agreement with...
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Supported Phospholipid Bilayers and their Interactions with Proteins Studied by Ellipsometry, Atomic Force Microscopy and Confocal Fluorescence Microscopy
Macháň, Radek ; Hof, Martin (advisor) ; Fidler, Vlastimil (referee) ; Konopásek, Ivo (referee)
Supported lipid bilayers have been used as an artificial model of biological membranes and their interaction with 5 selected antimicrobial peptides was studied by several experimental techniques, mainly ellipsometry, laser scanning microscopy and fluorescence correlation spectroscopy. The thesis explains basic principles of the applied techniques focusing on their aspects relevant to characterization of lipid bilayers. The biological significance of antimicrobial peptides, their modes of interaction with membranes and the basic characteristics of the selected peptides are briefly discussed. The following text describes the main types of experimental studies performed and the interpretation of their results. Peptide-induced changes in lipid bilayer morphology were characterized by ellipsometry and laser scanning microscopy. Most interesting effects were observed in the case of melittin, which induced formation of long lipid tubules protruding from the bilayer. Lipid lateral diffusion measured by fluorescence correlation spectroscopy can provide information on bilayer organization on length-scales below resolution of optical microscopy.
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Supported Phospholipid Bilayers and their Interactions with Proteins Studied by Ellipsometry, Atomic Force Microscopy and Confocal Fluorescence Microscopy
Macháň, Radek
Supported lipid bilayers have been used as an artificial model of biological membranes and their interaction with 5 selected antimicrobial peptides was studied by several experimental techniques, mainly ellipsometry, laser scanning microscopy and fluorescence correlation spectroscopy. The thesis explains basic principles of the applied techniques focusing on their aspects relevant to characterization of lipid bilayers. The biological significance of antimicrobial peptides, their modes of interaction with membranes and the basic characteristics of the selected peptides are briefly discussed. The following text describes the main types of experimental studies performed and the interpretation of their results. Peptide-induced changes in lipid bilayer morphology were characterized by ellipsometry and laser scanning microscopy. Most interesting effects were observed in the case of melittin, which induced formation of long lipid tubules protruding from the bilayer. Lipid lateral diffusion measured by fluorescence correlation spectroscopy can provide information on bilayer organization on length-scales below resolution of optical microscopy.
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Determination of permeability and active transport of selected butyrylcholinesterase inhibitors in vitro
Machan, Radek ; Červený, Lukáš (advisor) ; Čečková, Martina (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Radek Machan Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Determination of permeability and active transport of selected butyrylcholinesterase inhibitors in vitro European Medicine Agency (EMA) and Food and Drug Administration agency (FDA) emphasise drug membrane permeability and drug-drug interactions on ABC transporters expressed in physiological barriers should be investigated for compounds in preclinical studies or for those already clinically used but evidence free. In this work we aimed to assess the capability of several experimental butyrylcholinesterase inhibitors that had been designed to treat dementia to permeate blood-brain barrier and to elucidate role of ATP-binding (ABC) cassette transporters in this transport. For this purpose, we employed in vitro bidirectional transport study across monolayers formed by polarized and highly differentiated Caco-2 cells. The permeability values gained from measurements were similar to values of several commonly used drugs for treatment of CNS disorders (e.g. antidepressants, antiepileptics). In addition, the compounds showed values of efflux ratio (basolateral- to-apical/apical-to-basolateral) approximately one...
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Supported Phospholipid Bilayers and their Interactions with Proteins Studied by Ellipsometry, Atomic Force Microscopy and Confocal Fluorescence Microscopy
Macháň, Radek ; Hof, Martin (advisor) ; Fidler, Vlastimil (referee) ; Konopásek, Ivo (referee)
Supported lipid bilayers have been used as an artificial model of biological membranes and their interaction with 5 selected antimicrobial peptides was studied by several experimental techniques, mainly ellipsometry, laser scanning microscopy and fluorescence correlation spectroscopy. The thesis explains basic principles of the applied techniques focusing on their aspects relevant to characterization of lipid bilayers. The biological significance of antimicrobial peptides, their modes of interaction with membranes and the basic characteristics of the selected peptides are briefly discussed. The following text describes the main types of experimental studies performed and the interpretation of their results. Peptide-induced changes in lipid bilayer morphology were characterized by ellipsometry and laser scanning microscopy. Most interesting effects were observed in the case of melittin, which induced formation of long lipid tubules protruding from the bilayer. Lipid lateral diffusion measured by fluorescence correlation spectroscopy can provide information on bilayer organization on length-scales below resolution of optical microscopy.
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Supported Phospholipid Bilayers and their Interactions with Proteins Studied by Ellipsometry, Atomic Force Microscopy and Confocal Fluorescence Microscopy
Macháň, Radek
Supported lipid bilayers have been used as an artificial model of biological membranes and their interaction with 5 selected antimicrobial peptides was studied by several experimental techniques, mainly ellipsometry, laser scanning microscopy and fluorescence correlation spectroscopy. The thesis explains basic principles of the applied techniques focusing on their aspects relevant to characterization of lipid bilayers. The biological significance of antimicrobial peptides, their modes of interaction with membranes and the basic characteristics of the selected peptides are briefly discussed. The following text describes the main types of experimental studies performed and the interpretation of their results. Peptide-induced changes in lipid bilayer morphology were characterized by ellipsometry and laser scanning microscopy. Most interesting effects were observed in the case of melittin, which induced formation of long lipid tubules protruding from the bilayer. Lipid lateral diffusion measured by fluorescence correlation spectroscopy can provide information on bilayer organization on length-scales below resolution of optical microscopy.
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Comprehensive characterization of cellular suspensions by means of elastic light scattering
Macháň, Radek ; Štěpánek, Josef (advisor) ; Plášek, Jaromír (referee)
Studies of yeast Saccharomyces cerevisiae - a model eukaryot organism - often require determining the number of cells in a suspension. One of the methods often used for studying cell suspensions is the measuring of elastic scattering of light passing through the suspensions. Usual output of those measurements is the angular dependency of the intensity of scattered light, which bears information about the size of scatterers. This thesis studies time-dependencies of the intensity of scattered light and relationship of their statistical properties to the number of scatterers in a unit volume. For this purpose a simple model was proposed, which describes the connection between this quantity for a monodisperse suspension and the dependency of standard deviation of time-behaviour of the scattered intensity on the mean value of the same time-behaviour. An apparatus for computer controlled measurements of angular and timedependencies of scattered light intensity was completed for carrying out the experiments. Elastic scattering was measured on suspensions of yeast Saccharomyces cerevisiae and a model system (suspensions of 8m polymer particles). Experimental data were interpreted within the proposed model. Although yeast suspensions cannot be regarded as monodisperse, experimental data were in a good agreement with...
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